Custom widget for QtCreator, QLabel problem

Hi,
I'm trying to implement a drag-and-drop feature in my application, so I created couple widgets as QtDesginer plugins, co i can put those visually in QtCreator.
First widget is an Icon widget which should be draggable and second widget is a container from which icons should be dragged over to another widget.

Icon widget is created as QWidget with vertical layout and two QLabel objects - one for QPixmap icon and second for displaying name.

here is the code for the icon widget :

Code:

#ifndef DRAGGABLEICONWIDGET_H
#define DRAGGABLEICONWIDGET_H
 
#include <QWidget>
#include <QFrame>
#include <QLabel>
#include <QMetaProperty>
#include <QHBoxLayout>
#include <QVBoxLayout>
#include <QPixmap>
 
class DraggableIconWidget : public QWidget
{
    Q_OBJECT
    Q_PROPERTY(QString group READ group WRITE setGroup)
    Q_PROPERTY(QString name READ name WRITE setName)
    Q_PROPERTY(QString displayName READ displayName WRITE setDisplayName)
    Q_PROPERTY(QPixmap icon READ icon WRITE setIcon)
public:
    DraggableIconWidget(QWidget *parent = 0);
 
    QString group();
    void setGroup(QString);
 
    QString name();
    void setName(QString);
 
    QString displayName();
    void setDisplayName(QString);
 
    QPixmap icon();
    void setIcon(QPixmap);
private:
    QString group_;
    QString name_;
    QString displayName_;
    QPixmap icon_;
 
    QLabel *iconLabel_;
    QLabel *nameLabel_;
    QVBoxLayout *layout_;
};
 
#endif

Code:

#include "draggableiconwidget.h"
 
DraggableIconWidget::DraggableIconWidget(QWidget *parent) :
    QWidget(parent)
{
    iconLabel_ = new QLabel();
    iconLabel_->setAlignment(Qt::AlignCenter);
    iconLabel_->setText("");
 
    nameLabel_ = new QLabel();
    nameLabel_->setAlignment(Qt::AlignCenter);
    nameLabel_->setText("name");
 
    layout_ = new QVBoxLayout(this);
    layout_->addWidget(iconLabel_);
    layout_->addWidget(nameLabel_);
 
    this->setLayout(layout_);
}
 
QString DraggableIconWidget::group()
{
    return this->group_;
}
void DraggableIconWidget::setGroup(QString s)
{
    this->group_ = s;
}
QString DraggableIconWidget::name()
{
    return this->name_;
}
void DraggableIconWidget::setName(QString s)
{
    this->name_ = s;
}
QString DraggableIconWidget::displayName()
{
    return this->displayName_;
}
void DraggableIconWidget::setDisplayName(QString s)
{
    this->displayName_ = s;
    this->nameLabel_->setText(this->displayName_);
}
QPixmap DraggableIconWidget::icon()
{
    //this works fine in creator
    //return this->icon_;
    if(!this->iconLabel_->pixmap())
        return QPixmap();
    return *this->iconLabel_->pixmap();
}
void DraggableIconWidget::setIcon(QPixmap p)
{
    //this->icon_ = p;
    this->iconLabel_->setPixmap(p);
}

and here is the code for dragging function in the second custom widget:

Code:

void DragWidget::mousePressEvent(QMouseEvent *e)
{
    DraggableIconWidget *widget = static_cast<DraggableIconWidget*>(childAt(e->pos()));
    if(!widget)
        return;
 
    QPixmap pixmap = widget->icon(); //it crash here
    QString data = widget->group() + ":" + widget->name();
 
    QMimeData *mimeData = new QMimeData();
    mimeData->setText(data);
 
    QDrag *drag = new QDrag(this);
    drag->setMimeData(mimeData);
    drag->setPixmap(pixmap);
    drag->setHotSpot(e->pos() - widget->pos());
 
    QPixmap tempPixmap = *widget->iconLabel()->pixmap();
    QPainter painter;
    painter.begin(&tempPixmap);
    painter.fillRect(pixmap.rect(),QColor(127,127,127,127));
    painter.end();
 
    if(drag->exec(Qt::CopyAction | Qt::MoveAction,Qt::CopyAction) == Qt::MoveAction)
    {
        widget->close();
    }
    else {
        widget->show();
        widget->setIcon(pixmap);
    }
}

the problem is with getting the pixmap back from QLabel object. if the icon() function which return the pixmap, would be without the if statment the QtCreator is crashing everytime I try to open *.ui file and the same thing is when i'm trying to get the pixmap from item in my custom frame widget for dragging.

It works fine in QtCreator (loads .ui files and i can change the object icon) when i'm using second variable QPixmap icon_ in the class, and in the icon() function i return the this->icon_ variable, but then it also will crash when I'm trying to obtain pixmap form within the second widget.

Previously i was using my own widget for icons, but It was based on QLabel object, and then dragging and everything else was fine, but then i can't add second label with text so I must find another way for doing it.

here is the stack dump:

Code:

0	QScopedPointer<QObjectData, QScopedPointerDeleter<QObjectData> >::data	qscopedpointer.h	135	0xe27a2e	
1	qGetPtrHelper<QScopedPointer<QObjectData, QScopedPointerDeleter<QObjectData> > >	qglobal.h	2455	0xa73637	
2	QLabel::d_func	qlabel.h	166	0xe5add8	
3	QLabel::pixmap	qlabel.cpp	437	0xa6e575	
4	DraggableIconWidget::icon	draggableiconwidget.cpp	48	0x401d16	
5	DragWidget::mousePressEvent	dragwidget.cpp	14	0x4015bb	
6	QWidget::event	qwidget.cpp	8371	0x6d6370	
7	QFrame::event	qframe.cpp	557	0xa6ac28	
8	QApplicationPrivate::notify_helper	qapplication.cpp	4562	0x68bf46	
9	QApplication::notify	qapplication.cpp	4105	0x68a190	
10	QCoreApplication::notifyInternal	qcoreapplication.cpp	946	0x69dd5a1a	
11	QCoreApplication::sendSpontaneousEvent	qcoreapplication.h	234	0xd2653a	
12	QApplicationPrivate::sendMouseEvent	qapplication.cpp	3171	0x6889fc	
13	QETWidget::translateMouseEvent	qapplication_win.cpp	3365	0x6f31a9	
14	QtWndProc@16	qapplication_win.cpp	1698	0x6edf9e	
15	USER32!GetDC	C:\WINDOWS\system32\user32.dll		0x7e368734

To compile my custom widgets I used Qt 4.84 with MSVC compiler, and for building my test application i'm using Qt 4.8.4 with MinGw compiler
Everything was tested in QtCreator 2.8.0

Any ideas what could be wrong with my code ? Thnx in advance for any clues ;)